The machine's design included a circle of owls perched on a lithographed tin wheel.

In 1897, the company launched the Mills Owl, which was the first mechanical upright cabinet slot machine. Mills's patented 1891 contribution to cigar vending Over half a century later, the company would promote itself as having been founded in 1889, two years before the date of the patent, and by H.S. Cigar Vending Company sometime between 1891, and 1895. Focusing on the devices covered by the patent, Mortimer Mills founded the M.B.M. The improvement allowed the purchaser to select the product being sold and manipulate it so that it was carried to the point of delivery. Mortimer Mills was granted United States patent 450,336 on 14 April 1891 for an improvement in 'coin-actuated vending apparatus'.

Mills, Herbert's first son, taking over as president while his three brothers, Ralph, Herbert, and Hayden held other top management positions. In 1929, Herbert Mills had died aged 57, leaving a fortune to his wife and eight children. The Mills brothers were raised in Oak Park, Illinois, and continued to live in that area until at least the mid-1930s. His younger brother, Hayden ('Bill') Mills, was born two years later in about 1902. In about 1900, Herbert Mills, the third son of Herbert Stephen Mills was born. Mills, Herbert's second son, was born in July 1898. Mills, the first of Herbert Mills' sons, was born. Mills, the youngest of Mortimer Mill's children was born. One son, Herbert Stephen Mills, was born in 1872 when his father was about 27. The origins of the business lie with Mortimer Birdsul Mills, who was born in 1845 in Canada West (today's Ontario, Canada) but who later became a citizen of the United States, resident in Chicago, Illinois. By the late 1930s, vending machines were being installed by Mills Automatic Merchandising Corporation of New York. The slot machine division was then owned by Bell-O-Matic Corporation. By 1944, the name of the company had changed to Mills Industries, Incorporated. Between about 19, the company's products included the Mills Violano-Virtuoso and its predecessors, celebrated machines that automatically played a violin and, after about 1909, a piano. The Mills Novelty Company, Incorporated of Chicago was once a leading manufacturer of coin-operated machines, including slot machines, vending machines, and jukeboxes, in the United States.

Mills slot machine not paying out